“Clear signs that the sitcom is rebounding from its early-2000s slump are beginning to surface. Before this year, as onetime hits such as ‘Frasier,’ ‘Friends,’ and ‘Everybody Loves Raymond’ were saying their too-long goodbyes, the sitcom genre was viewed as a tired format with a musty TV Land vibe. But while there are fewer sitcoms on TV now, each of them seems to be working harder to stay alive.”